Process of making a helical gear



May 5, ma s s. @RAMER imam PROCESS OF MAKING A HELICAL GEAR OriginalFiled Nov. 50, 1934' ATTOR N EY Patented May 5, 1936 UNITED STATESPATENT OFFICE 2,039,707 PROCESS OF MAKING A HELIOAL GEAR Stanley S.Cramer, HaddonH eights, N. J., assignor to Radio Condenser Company,Camden, N. J.

4 Claims.

This invention relates to a helical gear and the process of constructingthe same this application being a division of application, Serial No.755,350 filed November 30, 1934.

It is the principal object of my invention to provide a helical gearwhich can be made with the simplest kind of machinery or apparatus andwithout the use of special cutters or complicated dies.

I have found, after considerable study, that it is possible to constructa helical gear having a predetermined desired helix or pitch fromlaminations having plain spur teeth thereon. Since spur teeth arerelatively simple in their design and may be readily punched on theperiphery of a piece of suitable material of a chosen thickness, a gearconstructed according to my process from such discs or laminations, maybe made very cheaply.

My invention will be readily understood by reference to the annexeddrawing, the different views of which illustrate one way in which myinvention may be carried out, and wherein:

Figure l is a plan view of a lamination or disc having spur teeth whichmay be punched directly from the stock from which the gear lamination ismade.

Figure 2 is a plan view of a fixture which may be used in making thehelical gear from the spur gear shown in Figure 1.

Figure 3 is a view of the fixture of Figure 2, but with a stack of spurgear discs of Figure 1 in position thereon.

Figure 4 is a view similar to Figure 3, but showing a binding orclamping plate with fastening means for holding the stack of laminationscomprising the gear in position.

Figure 5 is a View on the line 5-5 of Figure 2.

Figure 6 is a view on the line 6-6 of Figure 2, with the fixture tippedtoward the observer at an angle of ninety degrees.

Figure 7 is a view on the line of Figure 2, considered as in Figure 6.

Figure 8 is an enlarged view looking down on one of the assembly blocksof the fixture of Figure 2.

Figure 9 is an enlarged perspective View of a portion of the completedhelical gear.

Figure 10 is an enlarged view of one of the gearteeth shown in Figure 9.

In the various views, I is a gear having spur teeth 2 and a centermounting hole 3. For the purpose of my process of making a helical gearfrom such a gear as shown in Figure 1, the gear I is made of anysuitable relatively thin material-- for example, in some cases I pref-erto make this gear of non-metallic material such as fibrous materialtreated with some compound, micarta being illustrative of such anarrangement. When using micarta, I may use a thickness of materialvarying from .015" to .025", but I do not wish to be limited by thesethicknesses, they being merely illustrative of thicknesses of materialwhich I have successfully used in practice.

In carrying out my process of construction of the helical gear, Iprovide a fixture plate 4 having mounted thereon a plurality of assemblyblocks. One of these blocks, 5, is preferably pivotally mounted to theplate 4 as by screw 6. I have found it advisable to use additionalblocks 7 and 8 which may be screwed or riveted in permanently'fixedposition to the plate 4 in a manner as illustrated in Figure 2. Each ofthe blocks 5, l and 8 have teeth 9 cut or formed along one side or edgethereof. The teeth 9 are cut or formed at an angle to conform to thehelix or pitch of the gear with which the helical gear is to function.In order to facilitate initial assembly, the block 5 is pivotallymounted on the plate 4 as has been already noted, and the plate 4 isprovided with a hole II] to receive a stop pin for permanently locatingthe free end of the block 5.

With the blocks 5, I and 8 in position, the laminations or discs I arestacked on the fixture between the. blocks as shown in Figure 3, overthe opening II in the plate 4 and over the jig holes I2. After asuflicient number of laminations have been stacked to give the desiredthickness of gear, a clamp may be applied to the outer lamination andthe fixture turned over and a drill passed through the jig holes 12through the stack of laminations. Then a stiff metal binding plate l3having holes already formed therein according to the spacing of the jigholes I2, is applied to the top of the stack together with fasteningmeans [4 which may be solid or eyelet type of rivets, the latter beingillustrated. Then the pin may be removed from the hole In and the block5 swung away from the stack, which can then be removed by a, toolengaging the stack centrally or preferably through the openings l l andanother binding plate l3 applied to what was the bottom of the stack,and the fastening means set up into final locking position, therebycompleting the gear.

Due to the helical pitch of the teeth 9, each disc I as it is stacked onthe fixture will be arcuately turned on the common axis to positions asillustrated in Figures 9 and 10, with the result that a helical gear isobtained as described.

' Instead of the process of assembly as described, it is within thepurview of my invention to place the bottom binding plate I3 on thefixture by use 7 of a proper locating pin, so that the holes thereinwill register with the jig holes 12, so that after the fastening means[4 are inserted in position they will then protrude through the bottombinding plate. While it is preferable to punch the holes in the platesl3 when they are made, the plates may be plain blanks and drilled at thesame time that the lamination stack is drilled. Furthermore, the geardiscs may have holes 15 punched therein when the disc is blanked out, inwhich case the holes I5 are large enough to allow for the angulardisplacement of the disc so that when the stack of discs is completedthe fastening means M can be inserted through these holes and the holesin the binding plates l3, but such steps are all contemplated by myprocess.

What I claim is: V

1. The process of making a helical gear, which consists in first makinga plurality of relatively thin gear discs with spur teeth thereon,making a fixture having assembly blocks spaced thereon and jig holestherein, first making said blocks with teeth therein formed at an anglecorresponding to the pitch of the gear with which the gear is tofunction, stacking the discs on said fixture between said blocks withthe spur teeth of the discs in engagement with the teeth of said blocks,then making holes with the aid of said jig holes through said discswhile holding the discs, then applying to the top side of the disc stacka binding plate having holes therein corresponding to the holes madethrough the discs, passing fastening means through said plate and discholes, removing the stack from the fixture and then adding anotherbinding plate over the thin gear discs of non-metallic material withspur teeth thereon, making a fixture having assembly blocks spacedthereon and. jig holes therein, first making said blocks with teeththerein formed at an angle corresponding to the helix of the gear withwhich the gear is to function, stacking the discs between the blocks sothe spur teeth of the discs mesh with the inclined teeth on the blocks,then drilling the stack through said jig holes while holding the discsin assembled position, applying to the top of the stack a binding platewith fastening means going through holes therein and through the drilledholes in the stack, removing the assembly from the fixture and addinganother binding plate to the other side of the stack and setting up thefastening means.

-3. The process of making a helical gear, which consists in first makinga plurality of thin discs with spur teeth thereon, assembling said discson a fixture having parts with teeth thereon inclined according to apredetermined helix, the assembly consisting in meshing at least some ofthe spur teeth of the discs with the teeth on said fixture parts, thencompleting the gear by fastening suitable binding plates to the oppositefaces of the gear.

4. The process of making a helical gear, which consists in first makinga plurality of thin discs with spur teeth thereon, assembling said discsWith successive laminations uniformly arcuately offset by causing theteeth therein to engage teeth formed in a fixture according to apredetermined helix, then completing the gear by fastening thelaminations securely together.

STANLEY S. CRAMER.

